Flexible and solid-state asymmetric supercapacitor based on ternary graphene/MnO2/carbon black hybrid film with high power performance

• Published in: Electrochimica acta Vol. 182; pp. 861 - 870
• Main Authors: Chen, Junchen, Wang, Yaming, Cao, Jianyun, Liu, Yan, Ouyang, Jia-Hu, Jia, Dechang, Zhou, Yu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.11.2015
• Subjects: asymmetric supercapacitor; carbon black; graphene; MnO2; MnO2; asymmetric supercapacitor; carbon black; graphene
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2015.10.015

[Display omitted] Solid-state ASC based on rGO/MnO2/CB (positive electrode) and rGO/CB (negative electrode) shows extended cell voltage of 1.8V and excellent power capability. Reduced graphene oxide/manganese dioxide/carbon black (rGO/MnO2/CB) ternary film is prepared by a simple vacuum filtration method. MnO2 nano particles grow on both sides of the graphene layers serving as active sites for the electrochemical reactions which remarkably enhance the specific capacitance. While CB acts as spacers between the graphene layers preventing the restacking of graphene sheets and improves the conductivity between the basal planes of graphene sheets, leading to a better rate performance. Thanks to the synergistic effects of CB and MnO2, the capacitanceis improved to 209Fg−1, which is much better than that of the binary graphene/CB film (96Fg−1) and maintains at 77Fg−1 even at a fastscan rate of 1Vs−1. The 1.8V aqueous asymmetric supercapacitor based on rGO/MnO2(2.5)/CB (positive electrode) and rGO/CB (negative electrode) exhibits a large energy density of 24.3Whkg−1 especially a high power delivery capability with an energy density of 10Whkg−1 at the power density of 45kWkg−1. Furthermore, the energy density of the flexible solid-state asymmetric device based on this ternary film reaches 20Whkg−1 and maintains 10Whkg−1 at the power density of 21kWkg−1.